| 摘要 |
Amides of type: (R. CO. NA)nR1.( (NCO)m, where R = residue after H-removal of a compound containing active H, especially the groups (n=3-11), R2.CO.NR3-(R2, R3 = alkyl), etc.), or an alcohol residue; A = Li and preferably Na or K; R1 = alkyl, aryl or aralkyl; n = 1-6, m = 0-5, are n + m = 1-6, preferably where n = 1-3 and m = 0, or n = 1-2 and m = 0-2, or n = 1 and m = 0; are made by reacting RH with an isocyanate and an alkali metal in an org. solvent, preferably in a hydrocarbon at its b.p. The products are useful for activating and catalyzing the polymerisation of lactams, especially those with 7-13 atoms in the ring, in hydrocarbon, ether,and dialkylamide solvents. Up to 2% is used, and the catalyst need not be isolated from the reaction mixture beforehand. |
